WO2014127558A1

WO2014127558A1 - Display device

Info

Publication number: WO2014127558A1
Application number: PCT/CN2013/073505
Authority: WO
Inventors: 鹿岛美纪
Original assignee: 京东方科技集团股份有限公司
Priority date: 2013-02-19
Filing date: 2013-03-29
Publication date: 2014-08-28
Also published as: US9164303B2; US20140293179A1; CN103149734B; CN103149734A

Abstract

A display device comprises a display panel (1) and a background panel (2) which are disposed opposite to each other, and an optical source (3) disposed on a side surface of the background panel (2), wherein the background panel (2) is in a transmitting state when no voltage is applied thereto, is in a light scattering state when a direct-current voltage is applied thereto, and is in a half-specular reflection and half-transmitting state when a high-frequency alternating-current voltage is applied thereto.

Description

Display device

Embodiments of the invention relate to a display device. Background technique

Due to its small size, low power consumption, and no radiation, liquid crystal displays have dominated the current flat panel display market. In the liquid crystal display, since the liquid crystal itself does not emit light, it only regulates the light transmitted light, so it is necessary to configure a light source (such as a backlight, a front light source or an external light source) for the liquid crystal display panel (also referred to as a liquid crystal display). In order to display the image.

With the rapid development of liquid crystal display technology, a transparent liquid crystal display has been proposed which utilizes external ambient light (including natural light, light emitted by an external light source) and light emitted by a transparent backlight to cause an image to be displayed on the liquid crystal display panel. . Liquid crystal displays generally use side-lit backlights, including light sources, light guides, and optical film sets. When the external ambient light is strong, the transparent liquid crystal display mainly uses the external ambient light as the light source, and when the ambient light is weak, the transparent liquid crystal display mainly uses the transparent backlight as the light source.

At present, such a transparent liquid crystal display has been applied to a refrigerator to become a "window" of a refrigerator, that is, a refrigerator window, which allows a user to see the food stored therein without opening the refrigerator. Moreover, according to different user groups, a series of humanized functions can be developed, such as displaying the shelf life and nutrients of stored foods, weather forecasts, leaving notes for family members, and even playing movies. However, since the power of the light source in the conventional transparent liquid crystal display is large, heat is generated, and when it is applied to the refrigerator, the storage of the refrigerated/frozen food is affected. SUMMARY OF THE INVENTION A display device with a small rate.

One aspect of the present invention provides a display device including an oppositely disposed display panel and a background panel, and a light source disposed on a side of the background panel; the background panel is in a transmissive state when no voltage is applied, when a DC voltage is applied Light scattering, half when high frequency AC voltage is applied Specular reflection semi-transmissive state.

For example, the background panel has different transmittances when different DC voltages are applied.

For example, the greater the DC voltage applied to the background panel, the lower its transmittance.

For example, the background panel includes a first substrate and a second substrate disposed opposite to each other, a cholesteric liquid crystal layer disposed between the first substrate and the second substrate, and disposed between the first substrate and the cholesteric liquid crystal layer a first electrode, and a second electrode disposed between the second substrate and the cholesteric liquid crystal layer.

For example, the cholesteric liquid crystal layer may employ a negative liquid crystal layer to which a chiral ionic liquid is added. For example, the display panel can be a normally white mode.

For example, the display panel may employ a liquid crystal display panel.

For example, the display device may further include an air layer disposed between the display panel and the background panel.

For example, the light source may be a light emitting diode or an electroluminescent sheet.

The display device of the embodiment of the present invention has four states of a transparent state, a transparent display state, a white state (ie, a light scattering state), and a white background display state, and has a display panel and a background panel. According to actual needs, you can switch between the above four states at any time, and the user experience is good. DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below. It is obvious that the drawings in the following description relate only to some embodiments of the present invention, rather than to the present invention. limit.

1 is a schematic structural diagram of a display device according to Embodiment 3 of the present invention;

2 is a schematic structural view of the background panel of FIG. 1.

Reference numerals: 1 - liquid crystal display panel; 2 - background panel; 3 - light source; 4 - air layer; 21 - first substrate; 22 - first electrode; 23 - cholesteric liquid crystal layer; 24 - second electrode; 25 - second substrate. detailed description

The technical solutions of the embodiments of the present invention will be clearly and completely described in the following with reference to the accompanying drawings. Obviously, The described embodiments are a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the described embodiments of the present invention without departing from the scope of the invention are within the scope of the invention.

Unless otherwise defined, technical terms or scientific terms used herein shall be of the ordinary meaning understood by those of ordinary skill in the art to which the invention pertains. The words "first", "second" and similar terms used in the specification and claims of the present invention do not denote any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the words "a", "an", "the" and the like do not denote a quantity limitation, but mean that there is at least one. The words "including" or "comprising", etc., are intended to mean that the elements or objects preceding "including" or "comprising" are intended to encompass the elements or Component or object. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "Down", "Left", "Right", etc. are only used to indicate the relative positional relationship. When the absolute position of the object to be described is changed, the relative positional relationship may also change accordingly.

Example 1

The embodiment provides a display device, including: a display panel and a background panel disposed opposite to each other, and a light source disposed on a side of the background panel; the background panel is in a transmissive state when no voltage is applied, and is light-scattered when a DC voltage is applied. The state is semi-specularly reflective and semi-transmissive when a high-frequency alternating voltage is applied.

The display panel may be any product or component having a display function such as a liquid crystal display panel, an electronic paper, an OLED panel, or the like.

For example, the light source is located outside of at least one side of the background panel.

The display device according to the embodiment can display four states, such as a transparent state, a transparent display state, a white state (ie, a light scattering state), and a white background display state, according to different states of the background panel, and can be The actual demand is switched between the above four states at any time.

Example 2:

The embodiment provides a display device, including: a display panel and a background panel disposed opposite to each other, and a light source disposed on a side of the background panel. In this embodiment, the display panel adopts a liquid crystal display panel. For example, the liquid crystal display panel can adopt the existing TN (Twisted Nematic) mode liquid crystal display panel, ADS (ADvanced Super Dimension Switch, advanced Super-dimensional field conversion technology) mode liquid crystal display panel or other mode liquid crystal display panel.

For example, the ADS mode is a core technology for a liquid crystal display plane electric field wide viewing angle, and its core technical characteristics are described as: an electric field generated by the edge of the slit electrode in the same plane and between the slit electrode layer and the plate electrode layer in different layers The generated electric field forms a multi-dimensional electric field, so that all the aligned liquid crystal molecules between the slit electrodes in the liquid crystal cell and directly above the electrode can be rotated, thereby improving the working efficiency of the liquid crystal and increasing the light transmission efficiency. ADS mode switching technology can improve the picture quality of TFT-LCD products, with high resolution, high transmittance, low power consumption, wide viewing angle, high aperture ratio, low chromatic aberration, and no push mura. . ADS technology improvements for different applications include high-transmission I-ADS technology, high aperture ratio H-ADS and high-resolution S-ADS. The structure and material of the liquid crystal display panel can be prepared by using the prior art, and will not be described again.

In this embodiment, by applying or not applying voltage to the background panel, and the cooperation of the background panel with the light source and the liquid crystal display panel, the display device can be controlled to display different states: for example, no voltage is applied to the background panel to make it transparent, and the liquid crystal display When the panel is in a transparent state, the display device also assumes a transparent state.

Applying a high-frequency alternating voltage (for example, 100 kHz) to the background panel to make it a semi-specular state, that is, a reflective semi-transmissive state, and the cooperation of the background panel with the light source and the liquid crystal display panel causes the liquid crystal display panel to display an image, that is, the light emitted by the light source After the specular reflection of the background panel enters the liquid crystal display panel, so that the liquid crystal display panel displays an image, the display device assumes a transparent display state. When the ambient light is strong, the power of the low light source can be adjusted to make full use of the ambient light. It can be seen that since the background panel is in a semi-specular reflection state when a high-frequency alternating voltage is applied, the light emitted from the light source is reflected to the liquid crystal display panel with little loss, so the background panel is applied with a high-frequency alternating current voltage. It not only plays the role of the light guide plate, but also has better effect than the light guide plate.

When a DC voltage is applied to the background panel to cause a light scattering state (i.e., a white state), and the liquid crystal display panel is in a transparent state, the display device assumes a white state.

Applying a DC voltage (for example, 40v) to the background panel to make it light scattering (in a white state), and the background panel cooperates with the light source and the liquid crystal display panel to cause the liquid crystal display panel to display an image, that is, the light emitted by the light source passes through the background panel. After the scattering enters the liquid crystal display panel, so that the liquid crystal display panel displays an image, the display device assumes a display state in which the background is white. It can be seen that since the background panel is in a light scattering state when a direct current voltage is applied, the light emitted from the light source is scattered and enters the liquid crystal display panel, so that the background panel can also function as a light guide plate when a direct current voltage is applied, but The light utilization rate is not as high as when the background panel is in a semi-mirror state, but since the background is in a white state, the display device has a better display effect than the background is in a transparent state.

Other structures and functions in this embodiment are the same as those in Embodiment 1, and are not described herein again.

Example 3

As shown in FIG. 1 , the embodiment provides a display device including a liquid crystal display panel 1 and a background panel 2 disposed opposite to each other, an air layer 4 disposed between the liquid crystal display panel 1 and the background panel 2, and a background panel. 2 light source 3 on the side of the circumference.

As shown in FIG. 2, the background panel 2 includes a first substrate 21 and a second substrate 25 disposed opposite to each other, a cholesteric liquid crystal layer 23 disposed between the first substrate 21 and the second substrate 25, and a first substrate 21 disposed. The first electrode 22 between the liquid crystal layer 23 and the cholesteric phase, and the second electrode 24 disposed between the second substrate 25 and the cholesteric liquid crystal layer 23.

For example, the first substrate 21, the first electrode 22, the cholesteric liquid crystal layer 23, the second electrode 24, and the second substrate 25 are disposed in parallel with each other, and the cross-sectional dimensions are equal.

For example, the first substrate 21 and the second substrate 25 are made of a transparent alkali-free glass substrate or a quartz substrate. The first electrode 22 and the second electrode 24 are made of a transparent metal oxide material, preferably an ITO (Indium Tin Oxide) film or an IZO (Indium Zinc Oxide) film.

The cholesteric liquid crystal layer 23 employs a negative liquid crystal layer to which a chiral ionic liquid is added. The chiral ionic liquid may be an imidazolium salt chiral ionic liquid, a quaternary ammonium salt chiral ionic liquid, a tetrazoline salt type chiral ionic liquid, a thiazoline salt type chiral ionic liquid or a pyridinium salt chirality. Ionic liquids, etc.

The cholesteric liquid crystal is a milky white viscous liquid, which has a layered molecular arrangement structure, that is, a molecular layered arrangement, which is laminated one by another; the long axes of the molecules in each layer are parallel to each other and are parallel to the layer; Connected into a space-distorted spiral, the cholesteric liquid crystals are arranged in a spiral structure. Embodiments of the present invention may employ cholesteric liquid crystals conventional in the art.

When no voltage is applied to the first electrode 22 and the second electrode 24 located on both sides of the cholesteric liquid crystal layer 23, the cholesteric liquid crystal layer 23 is in a transmissive state.

When a direct current voltage is applied to both sides of the first electrode 22 and the second electrode 24, the chiral ionic liquid in the cholesteric liquid crystal layer 23 migrates to the first electrode 22 and the second electrode 24, respectively, under the action of a direct current electric field (negative ions) Move to the positive electrode, positive ions move to the negative electrode), causing the negative liquid crystal molecules to appear The cone texture, the biliary liquid crystal layer 23 is in a light scattering state; and when the DC voltage applied to the both sides of the first electrode 22 and the second electrode 24 is different, the transmittance of the cholesteric liquid crystal layer 23 is also different, and the applied direct current is applied. The higher the voltage, the more the light is scattered toward the light scattering state. The lower the transmittance, the smaller the applied DC voltage is, the more it is biased toward the transparent state, and the higher the transmittance, the more the two electrodes 22 and the second electrode 24 can be applied. The magnitude of the DC voltage is used to adjust the transmittance of the biliary liquid crystal layer 23.

After the DC voltage applied on both sides of the first electrode 22 and the second electrode 24 is stabilized, the DC voltage is switched to a high-frequency AC voltage, so that the negative liquid crystal molecules are converted from the focal conic texture to the plane under the action of the high-frequency AC voltage. Texture, and the concentration of the negatively charged chiral ionic liquid near the positive electrode is large, and the spiral twisting force is strong, so that the pitch near the positive electrode becomes significantly smaller, and the concentration of the positively charged chiral ionic liquid near the negative electrode is small, and the spiral twisting force The weaker pitch makes the pitch near the negative electrode slightly larger, so that the gradient of the pitch is realized in the direction perpendicular to the first substrate and the second substrate, and the cholesteric liquid crystal layer 23 is in a semi-specular reflection semi-transmissive state. After the first electrode 22 and the second electrode 24 are de-energized for a period of time, or a reverse DC voltage is applied, the biliary liquid crystal layer 23 returns to the transmissive state.

For example, the liquid crystal display panel 1 is in a normally white mode. Since the display panel of the normally white mode does not apply a voltage, the effective display area of the display panel corresponding to the liquid crystal molecules is transparent; when the voltage is applied, the effective display area of the display panel corresponding to the liquid crystal molecules is opaque. When the display device of the embodiment is used as a refrigerator window, the display device is in a transparent state for most of the time or the background is in a transparent display state, so that the normally white mode liquid crystal display panel is more power-saving.

For example, when the liquid crystal display panel 1 is of a ΤΝ type, it includes an array substrate, a color filter substrate, and a nematic liquid crystal layer disposed between the array substrate and the color filter substrate. The structure and material of the array substrate and the color filter substrate can be prepared by using the prior art, and will not be described again.

For example, the light source 3 may be a light emitting diode (LED) or an electroluminescent light emitting sheet (EL), or a cold cathode fluorescent lamp or the like may be used.

The function of the air layer 4 is to further improve the utilization efficiency of light. The light includes both light emitted by the light source and ambient light (such as daylight). Those skilled in the art can adjust the thickness of the air layer 4 according to the actual situation.

Other structures and functions in this embodiment are the same as those in Embodiment 2, and are not described herein again.

The above is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims.

Claims

Claim

A display device comprising: a display panel and a background panel disposed opposite to each other, and a light source disposed on a side of the background panel; the background panel is in a transmissive state when no voltage is applied, and is in a light scattering state when a direct current voltage is applied A semi-specular reflection semi-transmissive state when a high-frequency alternating voltage is applied.

2. The display device according to claim 1, wherein the background panel has different transmittances when different DC voltages are applied.

The display device according to claim 2, wherein the larger the DC voltage applied to the background panel, the lower the transmittance.

The display device according to any one of claims 1 to 3, wherein the background panel includes a first substrate and a second substrate disposed opposite to each other, and a timid disposed between the first substrate and the second substrate a phase liquid crystal layer, a first electrode disposed between the first substrate and the cholesteric liquid crystal layer, and a second electrode disposed between the second substrate and the cholesteric liquid crystal layer.

The display device according to claim 4, wherein the cholesteric liquid crystal layer is a negative liquid crystal layer to which a chiral ionic liquid is added.

The display device according to claim 5, wherein the chiral ionic liquid is an imidazolium salt chiral ionic liquid, a quaternary ammonium salt chiral ionic liquid, a tetrazoline salt type chiral ionic liquid, or a thiazole. A porphyrin-based chiral ionic liquid or a pyridinium-based chiral ionic liquid.

The display device according to claim 4, wherein the first substrate and the second substrate are made of a transparent alkali-free glass substrate or a quartz substrate; and the first electrode and the second electrode are made of an ITO film or an IZO film.

The display device according to any one of claims 1 to 7, wherein the display panel is in a normally white mode.

The display device according to any one of claims 1 to 8, wherein the display panel employs a liquid crystal display panel.

The display device according to any one of claims 1 to 9, further comprising an air layer disposed between the display panel and the background panel.

The display device according to any one of claims 1 to 10, wherein the light source is a light emitting diode or an electroluminescent sheet.